You could use DrawingTools (Ctrl+D). However I do not recommend that because
it does not leave you with a permanent written specification of the graphic.
If you wanted to change the initial ParametricPlot part you would have to
redo all the hand-drawn parts. My experience is that custom graphics take
quite a bit of adjustment to finally obtain the result you want and it is
much better to work with a complete written specification that can be
modified and reevaluated.
The regular Mathematica paradigm for doing that is to use Epilog and Show
but this is just awkward enough to deter a large fraction of Mathematica
users. Items are not specified in a natural order and generally a great deal
of graphics level jumping is necessary.
The Presentations Application does allow you to work with a complete written
specification and to simply draw one item after another in a natural way.
Here is an example from the documentation showing how to produce a diagram
showing the geometry for calculating a center of mass. The example uses
custom scale lines with symbolic tick values, with the y axis on the right,
and is highly commented to show how each item is drawn one after another.
<<Presentations`
Module[
{xloc = 1, (* Vertical integration slice location *)
delx = .1, (* Depicted width of integration slice *)
yloc, cmyloc},
(* Calculation of top and midpoint of integration slice *)
yloc = (4 - xloc^2);
cmyloc = yloc/2;
(* The drawing statement *)
Draw2D[
{(* Draw the parabola with filling to the axis.
Notice that the Filling option affects how the parabola is drawn \
and must be in the Draw statement. *)
Draw[4 - x^2, {x, -2, 2}, Filling -> Axis],
(* Draw faint lines from the midpoint and top of slice to the \
vertical axis *)
{LightGray,
Line[{{xloc, cmyloc}, {2, cmyloc}}],
Line[{{xloc, yloc}, {2, yloc}}]},
(* Draw the vertical integration slice in transparent blue *)
{Opacity[.6, Legacy@RoyalBlue],
Rectangle[{xloc - delx, 0}, {xloc + delx, yloc}]},
(* Mark the center of mass of the vertical slice *)
CirclePoint[{xloc, cmyloc}, 2, Black, Blue],
(* Draw the horizontal and vertical scales with symbolic points \
marked *)
XSymbolicScale[{-2.2, 2.2, 0}, {-2.2,
2.2}, {{-2, -2}, {0, 0}, {xloc, x}, {2, 2}}],
YSymbolicScale[{0, 4.2, 2}, {0, 4.2},
{{cmyloc, (4 - x^2)/2, {-1, 0}}, {yloc, (4 - x^2), {-1, 0}}, {4,
4}},
0, -0.02, 0.03],
(* Label the center of mass of the slice, the x and y axis,
and add a larger font title to the graphic *)
Text["C.M.", {xloc, cmyloc}, {1.6, 0}],
Text[x, {2.4, 0}],
Text[y, {2, 4.4}],
Text[Style["Geometry for Calculating\nCenter of Mass", 16], {-2,
4.5}, {-1, 0}]} (*
End of the specification of the graphic primitives *),
(* The overall graphic options go here.
These are options that affect the overall appearance of the plot \
and have nothing to do with how individual items are drawn. *)
PlotRange -> {{-2.2, 3.4}, {-0.4, 5.0}},
BaseStyle -> {FontSize -> 12},
ImageSize -> 350]
]
David Park
djmpark at comcast.net
http://home.comcast.net/~djmpark/index.html
From: sam.takoy at yahoo.com [mailto:sam.takoy at yahoo.com]
Hi,
If I plot something using ParametricPlot and later want to add something to
the same plot, how is that done?
Many thanks in advance,
Sam